Display panel, display device and manufacturing method of the display panel

ABSTRACT

The present disclosure provides a display panel, a display device including the display panel, and a method of manufacturing the display panel. The display panel includes a substrate; a pixel-defining layer disposed on the substrate, wherein the pixel-defining layer defines a plurality of sub-pixel regions arranged in rows and columns; and an organic light emitting element disposed in at least one of the plurality of sub-pixel regions, wherein a side of the pixel-defining layer away from the substrate is provided with a groove, the groove has a depth less than a thickness of the pixel-defining layer, and the groove is disposed between the organic light emitting elements that are adjacent to each other and emit light of different colors.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is based upon International Application No.PCT/CN2019/096411, filed on Jul. 17, 2019, which is based upon andclaims the benefit of and priority to Chinese Patent Application No.201810982535.1 filed on Aug. 27, 2018, entitled “DISPLAY PANEL, DISPLAYDEVICE AND MANUFACTURING METHOD OF THE DISPLAY PANEL”, which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure generally relates to the field of displaytechnology and, more particularly, to a display panel, a display deviceincluding the display panel, and a manufacturing method of the displaypanel.

BACKGROUND

Organic light-emitting display devices are considered the nextgeneration of display devices due to various advantages, such as wideviewing angle, good contrast, and quick response.

When manufacturing an organic light emitting display device, respectivelayers of an organic light emitting element are generally formed by anevaporation process. However, since a high-precision mask used in theevaporation process may have an alignment error, adjacent organiclight-emitting elements (for example, the respective layers thereof)emitting different colors may attach to or overlap each other, resultingin display degradation.

It should be noted that the information disclosed in the backgroundsection above is only used to enhance the understanding of thebackground of the present disclosure, and therefore, may includeinformation that does not constitute the prior art known to those ofordinary skill in the art.

SUMMARY

The present disclosure provides a display panel, a display deviceincluding the display panel, and a manufacturing method of the displaypanel.

According to an aspect of the present disclosure, there is provided adisplay panel, including: a substrate; a pixel-defining layer disposedon the substrate, wherein the pixel-defining layer defines a pluralityof sub-pixel regions arranged in rows and columns; and an organic lightemitting element disposed in at least one of the plurality of sub-pixelregions, wherein a side of the pixel-defining layer away from thesubstrate is provided with a groove, the groove has a depth less than athickness of the pixel-defining layer, and the groove is disposedbetween the organic light emitting elements that are adjacent to eachand emit light of different colors.

In some embodiments of the present disclosure, the groove is disposedbetween the organic light emitting element emitting red light and theorganic light emitting element emitting green light which are adjacentto each other.

In some embodiments of the present disclosure, the depth of the grooveis larger than an entire thickness of the organic light emittingelement.

In some embodiments of the present disclosure, an angle formed by asidewall of the groove and a bottom surface of the groove is not lessthan 142 degrees.

In some embodiments of the present disclosure, the pixel-defining layerincludes a first sub-layer and a second sub-layer, the first sub-layerhas a first via hole passing through the first sub-layer, and the secondsub-layer are disposed at least in the first via hole to define thegroove.

In some embodiments of the present disclosure, the second sub-layercovers at least a part of a surface of the first sub-layer away from thesubstrate.

In some embodiments of the present disclosure, a material of the firstsub-layer is different from the material of the second sub-layer.

According to another aspect of the present disclosure, there is provideda display device, including any one of the display panels.

According to yet another aspect of the present disclosure, there isprovided a method of manufacturing a display panel, comprising: forminga pixel-defining layer on a substrate, wherein the pixel-defining layerdefines a plurality of sub-pixel regions arranged in rows and columns;and forming an organic light emitting element in at least one of theplurality of sub-pixel regions, wherein a side of the pixel-defininglayer away from the substrate is formed to have a groove, the groove hasa depth less than a thickness of the pixel-defining layer and, thegroove is disposed between the organic light emitting elements that areadjacent to each other and emit light of different colors.

In some embodiments of the present disclosure, the step of forming apixel-defining layer on a substrate includes: depositing a firstpixel-defining material on the substrate; patterning the firstpixel-defining material to form a plurality of first openings exposingthe plurality of sub-pixel regions respectively and a plurality of firstvia holes between at least two adjacent first openings; and depositingand patterning a second pixel-defining material on the firstpixel-defining material and the plurality of first via holes, to formthe plurality of grooves at positions corresponding to the plurality offirst via holes.

In some embodiments of the present disclosure, the first via hole passesthrough the first pixel-defining material.

In some embodiments of the present disclosure, the step of forming apixel-defining layer on a substrate includes depositing a pixel-definingmaterial on the substrate; patterning the pixel-defining material toform a plurality of first openings exposing the plurality of sub-pixelregions respectively; and patterning the pixel-defining material to formthe plurality of grooves.

In some embodiments of the present disclosure, the step of forming apixel-defining layer on a substrate includes: depositing a firstpixel-defining material on the substrate; patterning the firstpixel-defining material to form a plurality of first openings exposingthe plurality of sub-pixel regions respectively and a plurality of firstvia holes passing through the first pixel-defining material between thefirst openings adjacent to each other; and depositing a secondpixel-defining material in the plurality of first via holes to form theplurality of grooves.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the present disclosure, and are incorporated in andconstitute a part of this application. The drawings illustrateembodiments of the present disclosure and, together with thedescription, serve to explain the principles of the present disclosure.In the drawings:

FIG. 1 is a schematic view schematically showing a display panel;

FIG. 2 is a schematic view schematically showing a display panelaccording to an embodiment of the present disclosure;

FIG. 3 is a plan view schematically showing a display panel according toan embodiment of the present disclosure;

FIGS. 4a-4d are schematic views schematically illustrating forming apixel-defining layer on a substrate according to an embodiment of thepresent disclosure;

FIGS. 5a-5d are schematic views schematically illustrating forming apixel-defining layer on a substrate according to another embodiment ofthe present disclosure; and

FIGS. 6a-6d are schematic views schematically illustrating forming apixel-defining layer on a substrate according to still anotherembodiment of the present disclosure.

DETAILED DESCRIPTION

Exemplary embodiments of the present disclosure will now be describedmore fully with reference to the accompanying drawings. However, theembodiments can be implemented in various forms and should not beconstrued as limited to the examples set forth herein. Rather, theseembodiments are provided so that this disclosure will be morecomprehensive and complete, and will fully convey the concepts of thedisclosure to those skilled in the art. The described features,structures, or characteristics may be combined in any suitable manner inone or more embodiments.

For ease of description, spatially relative terms such as ‘below’,‘above’, ‘on’, ‘under’, etc. may be used herein to describe therelationship between one element or feature with other elements orfeatures as shown in the figures. It will be understood that spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientations described inthe figures.

It will also be understood that when the terms ‘comprising’ and/or‘including’ are used in this specification, the presence of statedfeatures, integers, steps, operations, elements, and/or components isstated, but that not exclude the existence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups thereof.

FIG. 1 is a schematic view schematically showing a display panel.

As shown in FIG. 1, the display panel includes a substrate 10, aplurality of first electrodes 20 formed on the substrate 10, apixel-defining layer 30 having a plurality of first openings 30 a thatexpose at least a portion (for example, a central portion) of theplurality of first electrodes 20, and a plurality of organic lightemitting elements formed on the plurality of first electrodes 20 in theplurality of first openings 30 a, wherein the plurality of organic lightemitting elements at least include a first organic light emittingelement 40 a and a second organic light emitting element 40 b.

During the manufacturing process, respective layers of the organic lightemitting elements 40 a and 40 b, such as a hole injection layer, a holetransport layer, an electron blocking layer, an emission layer, a holeblocking layer, an electron transport layer, and electron injectionlayer, are generally formed by an evaporation process.

However, due to an alignment error of a high-precision mask used in theevaporation process, the adjacent first organic light-emitting elements40 a and second organic light-emitting elements 40 b (for example, therespective layers thereof) emitting light of different colors may attachto or overlap on each other, as shown in region P1 in FIG. 1. Forexample, when an alignment accuracy of the mask is in the range of 8-10μm, and the distance between the two adjacent first openings of thepixel-defining layer 30 (i.e., the distance dl shown in FIG. 1) is 19μm, the organic light emitting elements 40 a and 40 b may have anattaching area or an overlapping area with a width of about 1 μm in theworst case, that is, when the masks used in forming two adjacent organiclight emitting elements 40 a and 40 b are both at the worst alignmentaccuracy.

Such attaching or overlapping may cause display degradation of thedisplay panel. For example, when the first organic light-emittingelement 40 a is an organic light-emitting element that emits red light,and the second light-emitting element 40 b is an organic light-emittingelement that emits green light, since the energy band gap of thelight-emitting material of the first organic light-emitting element 40 ais relatively narrow, parts of the holes transported in the secondorganic light emitting element 40 b (for example, the electron blockinglayer thereof) will be transported into the emission layer of the firstorganic light emitting element 40 a via the attaching area or theoverlapping area, and will be combined with electrons in the emissionlayer of the first organic light emitting element 40 a to emit redlight, thereby generating extra red light at the edge of the pixel thatemits red light. Especially in the case where the display panel displaysa white screen, the extra infrared generated as described above maycause the white screen to appear red, and the display of the displaypanel may be degraded.

FIG. 2 is a schematic view schematically showing a display panelaccording to an embodiment of the present disclosure.

As shown in FIG. 2, the display panel may include a substrate 10, aplurality of first electrodes 20, a pixel-defining layer 30, and organiclight emitting elements 40 a and 40 b. The plurality of first electrodes20 are formed on the substrate 10. The pixel-defining layer 30 has aplurality of first openings 30 a exposing at least a part of theplurality of first electrodes 20. The organic light emitting elements 40a and 40 b are formed on the exposed portion of the first electrodes 20,and include a first organic light emitting element 40 a and a secondorganic light emitting element 40 b that are adjacent to each other andemit light of different colors. The pixel-defining layer 30 also has agroove 30 b. The groove 30 b has a depth smaller than a thickness of thepixel-defining layer 30. For example, the groove 30 b may be formedwithout exposing the substrate 10. In addition, the groove 30 b isdisposed between the first organic light emitting element 40 a and thesecond organic light emitting element 40 b, which are adjacent to eachother and emit light of different colors.

Although not shown, the pixel-defining layer 30 may define a pluralityof sub-pixel regions on the substrate 10 which are arranged in rows andcolumns and in which the organic light-emitting elements are disposed.

FIG. 3 is a schematic plan view specifically showing arrangementpositions of the grooves 30 b in the organic light emitting elementmatrix according to an embodiment of the present disclosure.

As shown in FIG. 3, the pixel-defining layer 30 defines a plurality ofsub-pixel regions on the substrate, which are arranged in rows andcolumns and in which organic light-emitting elements 41 a-41 c aredisposed. The organic light emitting elements 41 a-41 c include a firstorganic light emitting element 41 a, a second organic light emittingelement 41 b, and a third organic light emitting element 41 c that emitlight of different colors. For example, the first organic light emittingelement 41 a, the second organic light emitting element 41 b, and thethird organic light emitting element 41 c may be an organic lightemitting element that emits red light, an organic light emitting elementthat emits green light, and an organic light emitting element that emitsblue, respectively.

The groove 30 b is disposed in the pixel-defining layer 30 and isdisposed between the first organic light emitting element 41 a thatemits red light and the second organic light emitting element 41 b thatemits green light. Here, a length of the groove 30 b may be equal to theshorter length of the lengths of the first and second organic lightemitting elements 41 a and 41 b. However, the present disclosure is notlimited thereto. The length of the groove 30 b may be longer than thelength of the second organic light emitting element 41 b which isshorter, as long as the first organic light emitting element 41 a andthe second organic light emitting element 41 b can be prevented from beoverlapped with each other, as described later.

In the display panel according to the present embodiment, the groove 30b is formed between the adjacent organic light emitting elements 40 aand 40 b that emit light of different colors in the pixel-defining layer30, thus display degradation caused by the attaching or overlapping(shown as in region P2 in FIG. 2) of the adjacent organic light emittingelements 40 a and 40 b that emit light of different colors can beprevented.

Specifically, when organic materials are evaporated to form the organiclight-emitting elements 40 a and 40 b, the organic material deposited inthe groove 30 b has poor uniformity because the material is notdeposited in a direction completely perpendicular to the substrate 10,but is diffused to a certain extent. Compared with the case where thegroove is not formed as shown in FIG. 1, the groove 30 b in thisembodiment can make the deposition distance of the organic materials ofthe organic light emitting elements 40 a and 40 b be longer, and furthermake respective thin film layers of the organic light emitting elements40 a and 40 b be thinner or even broken in the groove 30 b. There aremultiple corners in the groove 30 b, and these corners can make therespective film layers of the organic light emitting elements 40 a and40 b be bent and further broken.

Therefore, in the groove 30 b, at least one film layer of the organiclight emitting element 40 a and/or 40 b cannot be stably formed or maybe broken, so that the above-mentioned display degradation can beeffectively prevented.

The substrate 10 may be formed of a light-transmitting material such asglass or plastic. Although not shown, as will be recognized by thoseskilled in the art, a thin film transistor, a capacitor, a wiring, andthe like may be arranged on the substrate 10 to drive the organic lightemitting elements 40 a and 40 b to emit light.

The first electrode 20 may be a pixel electrode, which may include atransparent electrode formed of a transparent conductive material or areflective electrode formed of a reflective conductive material. Thetransparent conductive material may include ITO, IZO, and the like, andthe reflective conductive material may include Ag, Mg, Al, and the like,for example.

The pixel-defining layer 30 is formed on the substrate 10 and theplurality of first electrodes 20, and may be formed of an organicinsulating material such as an acrylic polymer. A plurality of firstopenings 30 a are formed in the pixel-defining layer 30 to expose atleast a portion of the plurality of first electrodes 20, for example, toexpose at least a central portion of the plurality of first electrodes20.

In addition, the groove 30 b is formed in the pixel-defining layer 30.Specifically, the groove 30 b is formed between organic light emittingelements 40 a and 40 b that are adjacent to each other and emit light ofdifferent colors, and has a depth smaller than a thickness of thepixel-defining layer 30 as described above. In other words, a verticaldistance from the top of the pixel-defining layer 30 to the bottom ofthe groove 30 b is smaller than the thickness of the pixel-defininglayer 30 such that the pixel-defining layer 30 cannot be penetrated bythe groove 30 b.

The groove 30 b may have a plurality of corners, for example, a cornerformed by the top of the pixel-defining layer 30 and the wall of thegroove 30 b, so that the light emitting material formed in the groove 30b is bent by the corner, thereby preventing the above mentioned displaydegradation.p

In some embodiments of the present disclosure, the groove 30 b may havea flat bottom surface, as shown in FIG. 2. Therefore, a corner may beformed at the bottom of the groove 30 b, so that the light emittingmaterial formed in the groove 30 b is bent by the corner at the bottomof the groove 30 b, thereby preventing the above mentioned displaydegradation. According to an exemplary embodiment of the presentdisclosure, an angle formed between a bottom surface of the groove 30 band a sidewall of the groove 30 b (as shown by A in FIG. 2) may be notless than 142 degrees, and preferably 150 to 155 degrees, in order toprevent the organic light emitting elements emitting light of differentcolors from being overlapped with each other.

In some embodiments of the present disclosure, the depth of the groove30 b may be greater than the thickness of the organic light emittingelements 40 a and 40 b. In this case, the thicknesses of the respectivefilm layers of the organic light emitting elements 40 a and 40 b formedin the groove 30 b may be thinner and the uniformity thereof may beworse.

In addition, as shown in FIG. 2, the wall of the groove 30 b may beinclined with respect to the bottom of the groove 30 b. Therefore, thearea of the bottom of the groove 30 b may be smaller than the area ofthe upper opening of the groove 30 b.

In some embodiments of the present disclosure, the groove 30 b may bedisposed between the organic light emitting element emitting red lightand the organic light emitting element emitting green light, which areadjacent to each other, thereby preventing the occurrence of suchdisplay defects: in the case where the organic light emitting elementemitting red light and the organic light emitting element emitting greenlight are attached or overlapped, since the energy band gap of the lightemitting material of the organic light emitting element emitting redlight is relatively narrow, parts of holes transported in the organiclight emitting element emitting green light (for example, the electronblocking layer thereof) will be transported into the organic lightemitting element emitting red light via the attaching area or theoverlapping area, and will be combined with electrons in the emissionlayer of the organic light emitting element emitting red light to emitred light. However, the present disclosure is not limited thereto, andthe grooves 30 b may be disposed between the adjacent organic lightemitting elements that emit light of any different colors to prevent thedisplay degradation caused by the attaching or overlapping of theorganic light emitting elements that emit light of different colors.

The organic light emitting elements 40 a and 40 b that emit light ofdifferent colors may be formed in the plurality of first openings 30 a,respectively. The organic light emitting elements 40 a and 40 b may beorganic light emitting diodes (OLED), respectively. The organic lightemitting elements 40 a and 40 b each include an emission layer, and mayfurther include at least one of a hole injection layer, a hole transportlayer, an electron blocking layer, a hole blocking layer, an electrontransport layer, and an electron injection layer.

In addition, although not shown, the display panel according to anembodiment of the present disclosure may further include a secondelectrode as an opposite electrode. The second electrode may be disposedon the organic light emitting elements 40 a and 40 b. In addition, thesecond electrode may be further formed on the pixel-defining layer 30 tocorrespond to the entire display panel, thereby serving as a commonelectrode.

An exemplary embodiment of the present disclosure also provides adisplay device including any of the above display panels, for example,an OLED display device.

A method of manufacturing the above-described display panel according toan exemplary embodiment of the present disclosure will now be describedin detail with reference to the accompanying drawings.

As shown in FIG. 2, a plurality of first electrodes 20 may be firstlyformed on a substrate 10. In some embodiments of the present disclosure,an electrode material of the first electrode 20 may be deposited on thesubstrate 10, and the plurality of first electrodes 20 may be formed bypatterning the deposited electrode material.

Then, a pixel-defining layer 30 is formed on the substrate 10. Here, thepixel-defining layer 30 is formed to have a plurality of first openings30 a exposing at least a part of the plurality of first electrodes 20,and is also formed to have a groove 30 b, the groove 30 b has a depthsmaller than a thickness of the pixel-defining layer 30 and is disposedbetween the adjacent first openings 30 a in which organic light emittingelements that emit light of different colors will be formed. The stepsof forming the pixel-defining layer 30 on the substrate 10 will bedescribed in detail below with reference to FIGS. 3a to 5 d.

Next, organic light emitting elements 40 a and 40 b are formed on theexposed portions of the first electrodes 20. Specifically, first organiclight emitting elements 40 a emitting light of a first color may beformed in a first part of the plurality of first openings 30 a by theevaporation process, and second organic light emitting elements 40 bemitting light of a second color may be formed in a second part of theplurality of first openings 30 a by the evaporation process.

According to an exemplary embodiment of the present disclosure, a secondelectrode may also be formed on the organic light emitting elements 40 aand 40 b. The second electrode may be further formed on thepixel-defining layer 30 as a common electrode corresponding to theentire display panel.

Next, the steps of forming a pixel-defining layer on a substrateaccording to an exemplary embodiment of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

FIGS. 4a-4d are schematic views schematically illustrating forming apixel-defining layer on a substrate according to an embodiment of thepresent disclosure.

As shown in FIGS. 4a and 4b , a first pixel-defining material 30-1 isdeposited on the substrate 10 to cover the substrate 10 and theplurality of first electrodes 20.

As shown in FIG. 4c , the first pixel-defining material 30-1 is etchedto form a plurality of first openings 30 a-1 exposing at least a part ofthe plurality of first electrodes 20 and a plurality of first via holes30 b-1 between the adjacent first openings 30 a-1. The first opening 30a-1 is etched to expose at least a portion of the first electrode 30,for example, at least a central portion thereof. The first via hole 30b-1 is etched to expose a part of the substrate 10, however, the presentdisclosure is not limited thereto, and for example, the first via hole30 b-1 may be etched to expose the substrate 10. Furthermore, accordingto an exemplary embodiment of the present disclosure, the first opening30 a-1 and the first via hole 30 b-1 having different depths may beformed by different etching steps, however, the present disclosure isnot limited thereto, and for example, the first opening 30 a-1 and thefirst via hole 30 b-1 may be etched to have the same depth by the sameetching steps.

As shown in FIG. 4d , a second pixel-defining material 30-2 is depositedon the first pixel-defining material 30-1 and the plurality of first viaholes 30 b-1, and thus the plurality of first openings 30 a are formedat the positions of the plurality of first openings 30 a-1, and theplurality of grooves 30 b are formed at the positions of the pluralityof first via holes 30 b-1.

Here, a mask may be used to deposit the second pixel-defining material30-2 on the first pixel-defining material 30-1 and the plurality offirst via holes 30 b-1 to prevent the second pixel-defining material30-2 from being deposited in the first opening 30 a-1. According to anexemplary embodiment of the present disclosure, the first pixel-definingmaterial 30-1 and the second pixel-defining material 30-2 may bedifferent, but the present disclosure is not limited thereto, and thefirst pixel-defining material 30-1 and the second pixel-definingmaterial 30-2 can be the same.

The via hole herein refers to passing through the first pixel material,and the shape of the via hole is not limited. The shape of the via holealong a cross section parallel to the substrate may be a square, acircle, a polygon, or the like.

FIGS. 5a to 5d are schematic views schematically illustrating forming apixel-defining layer on a substrate according to another embodiment ofthe present disclosure.

As shown in FIGS. 5a and 5b , a pixel-defining material 30′ is depositedon the substrate 10 to cover the substrate 10 and the plurality of firstelectrodes 20.

As shown in FIG. 5c , the pixel-defining material 30′ is etched to forma plurality of first openings 30 a exposing at least a portion (e.g., atleast a central portion) of the plurality of first electrodes 20.

As shown in FIG. 5d , the pixel-defining material 30′ is etched to forma plurality of grooves 30 b.

That is, in the embodiment shown in FIGS. 5a to 5d , the first opening30 a and the groove 30 b are formed by different etching steps.

FIGS. 6a to 6d are schematic views schematically illustrating forming apixel-defining layer on a substrate according to still anotherembodiment of the present disclosure.

As shown in FIGS. 6a and 6b , a first pixel-defining material 30-1 isdeposited on the substrate 10 to cover the substrate 10 and theplurality of first electrodes 20.

As shown in FIG. 6c , the first pixel-defining material 30-1 is etchedto form a plurality of first openings 30 a exposing at least a portion(for example, at least a central portion) of the plurality of firstelectrodes 20 and a plurality of previous grooves 30 b′ which arebetween the adjacent first openings 30 a and expose the substrate 10.

As shown in FIG. 6d , a second pixel-defining material 30-2 is depositedin the plurality of previous grooves 30 b′ to form a plurality ofgrooves 30 b.

According to an exemplary embodiment of the present disclosure, thefirst pixel-defining material 30-1 and the second pixel-definingmaterial 30-2 may be different, but the present disclosure is notlimited thereto, and the first pixel-defining material 30-1 and thesecond pixel-defining material 30-2 can be the same.

The foregoing description of specific exemplary embodiments of thepresent disclosure has been given with reference to the drawings. Theseexemplary embodiments are not intended to be exhaustive or to limit thepresent disclosure to the precise forms disclosed, and it is apparentthat those skilled in the art can make many modifications and changes inlight of the above teachings. Therefore, the scope of the presentdisclosure is not intended to be limited to the foregoing embodiments,but is intended to be defined by the claims and their equivalents.

What is claimed is:
 1. A display panel, comprising: a substrate providedwith a first organic light emitting element and a second organic lightemitting element which are adjacent to each other and configured to emitlight of different colors; and a pixel-defining layer disposed on thesubstrate, the pixel-defining layer having a first opening and a secondopening for exposing the first organic light emitting element and thesecond organic light emitting element, respectively, and having a groovedisposed on a side of the pixel-defining layer away from the substrate,wherein: the groove is disposed in the pixel-defining layer between thefirst opening and the second opening, and has a depth less than athickness of the pixel defining layer; the pixel-defining layercomprises a first sub-layer and a second sub-layer, the first sub-layerhas a first via hole passing through the first sub-layer, and the secondsub-layer is disposed on at least in the first via hole to form thegroove; and a material of the first sub-layer is different from amaterial of the second sub-layer, and the material of the secondsub-layer is different from a material of the first organic lightemitting element and a material of the second organic light emittingelement.
 2. The display panel according to claim 1, wherein the firstorganic light emitting element emits red light and the second organiclight emitting element emits green light.
 3. The display panel accordingto claim 1, wherein the depth of the groove is larger than a thicknessof the first organic light emitting element and the second organic lightemitting element.
 4. The display panel according to claim 1, wherein anangle formed by a sidewall of the groove and a bottom surface of thegroove is not less than 142 degrees.
 5. The display panel according toclaim 1, wherein the second sub-layer covers at least a part of asurface of the first sub-layer away from the substrate.
 6. A method ofmanufacturing a display panel, comprising: forming a pixel-defininglayer on a substrate; forming a first opening and a second openingadjacent to each other and a groove between the first opening and thesecond opening in the pixel-defining layer; and forming a first organicemitting element and a second organic emitting element in the firstopening and the second opening, respectively, wherein the first organicemitting element and the second organic emitting element emit light ofdifferent colors, wherein the groove has a depth less than a thicknessof the pixel-defining layer, wherein forming the first opening and thesecond opening adjacent to each other and the groove between the firstopening and the second opening in the pixel-defining layer comprises:patterning a pixel-defining material to form the first opening and thesecond opening and a via hole between the first opening and the secondopening, the via hole passing through the pixel-defining material; anddepositing and patterning another pixel-defining material at least inthe via hole to form the groove at a position corresponding to the viahole, wherein the pixel-defining material is different from said anotherpixel-defining material, and said another pixel-defining material isdifferent from a material of the first organic light emitting elementand a material of the second organic light emitting element.
 7. Themethod of manufacturing a display panel according to claim 6, whereindepositing and patterning said another pixel-defining material at leastin the via hole to form the groove at the position corresponding to thevia hole comprises: depositing and patterning said anotherpixel-defining material on the pixel-defining material and in the viahole to form the groove at the position corresponding to the via hole.8. The method of manufacturing a display panel according to claim 6,wherein depositing and patterning said another pixel-defining materialat least in the via hole to form the groove at the positioncorresponding to the via hole comprises: depositing said anotherpixel-defining material in the via hole to form the groove.